1. Field of the Invention
This invention relates to an apparatus for holding a cover of a lamp assembly of a vehicle, and more particularly to an apparatus for holding a rubber or elastic cover which is removably mounted on a holder of a lamp assembly of a vehicle and covers a bulb exchange opening from rain or water.
2. Background Art
FIG. 3 shows a prior-art apparatus for holding a rubber cover 80 on a hollow cylindrical holder 91 of a lamp assembly 90 of a vehicle. The holder 91 defines a bulb exchange opening and has outer engagement claws 91a formed at its plural (e.g. three) circumferential positions. The lamp assembly 90 comprises a separate cap 92 having hooks 92a engageable with the outer engagement claws 91a. In mounting, an outwardly extending flange 80a of the cover 80 is in contact with the top edge surface of the holder 91, the cap 92 is then placed over the holder 91 to sandwich the flange 80a of the cover 80 with the top edge surface of the holder 91, and the cap 92 is then rotated for engaging the hooks 92a with the outer engagement claws 91a of the holder 91.
Each of the hooks 92a has a tapered portion 92b and a concavely stepped portion 92c so that the cap 92 forcibly presses the flange 80a between the cap 92 and the holder 91 as an operator rotates the cap 92. Thereby the apparatus secures a tight seal of the interior of the lamp assembly against rain or water. Further, when the outer engagement claws 91a reach the concavely stepped portions 92c, fingers of the operator feel a physical response by which he or she realizes that the cap 92 has been set in place. The concavely stepped portions 92c also prevent the cap 92 from rotating in the reverse direction in service of the lamp assembly 90 to increase reliability of the function of the cap 92 of retaining the cover 80 on the holder 91.
In the prior-art apparatus, the retention of the cap 92 on the holder 91 and the physical response of the operator are attributed to elasticity of the flange 80a of the rubber cover 80. Therefore, if the cover 80 loses elasticity due to aging, then the operator feels no physical response in mounting the cover 80 on the holder 91, and the cap 92 cannot securely retain the cover 80 on the holder 91. Thus, reliability of the holder 91 and the cap 92 in retaining the cover 80 in a rain-tight manner decreases. The solution of such problem therefore has been desired.